Inductive coil structure and inductively coupled plasma generation system

ABSTRACT

An inductively-coupled plasma (ICP) generation system may include a dielectric tube, a first inductive coil structure to enclose the dielectric tube, an RF power supply, a first main capacitor between a positive output terminal of the RF power supply and one end of the first inductive coil structure, and a second main capacitor between a negative output terminal of the RF power supply and an opposite end of the first inductive coil structure. The first inductive coil structure may include inductive coils connected in series to each other and placed at different layers, the inductive coils having at least one turn at each layer, and auxiliary capacitors, which are respectively provided between adjacent ones of the inductive coils to distribute a voltage applied to the inductive coils.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority toPCT/KR2017/012040 filed on Oct. 30, 2017, which claims priority to KoreaPatent Application No. 10-2016-0146058 filed on Nov. 3, 2016, theentireties of which are both hereby incorporated by reference.

BACKGROUND

The present disclosure relates to an inductively-coupled plasma (ICP)generation system, and in particular, to an ICP generation systemincluding a capacitor interposed between a plurality of antennas andhaving a voltage division structure.

Plasma is used for a process of etching a substrate (e.g., asemiconductor wafer) or of depositing a layer the substrate.Furthermore, the plasma is used for synthesis of new materials, surfacetreatment, and environment purification. In addition, an atmosphericpressure plasma is used for plasma scrubber, cleaning, sterilization,and skin care.

To generate a conventional inductively-coupled plasma (ICP), adielectric discharge tube wound by an inductive coil is used. However,the conventional inductive coil structure suffers from low dischargestability and a low plasma density.

The present invention provides a novel inductive coil structure, whichis configured to stably generate inductively-coupled plasma at anatmospheric pressure or a high pressure of several Torr or higher.

SUMMARY

Some embodiments of the inventive concept provide an inductive coilstructure, which is used to produce inductively-coupled plasma withimproved discharge stability and efficiency while suppressingcapacitive-coupling components.

Some embodiments of the inventive concept provide an inductive coilstructure, which is configured to prevent a voltage increase caused byan increase in the winding number of an inductive coil, and a plasmageneration system including the same.

Some embodiments of the inventive concept provide an inductive coilstructure, which is configured to maximally increase the number ofwindings per unit length and to suppress capacitive coupling.

According to some embodiments of the inventive concept, aninductively-coupled plasma (ICP) generation system may include adielectric tube extending in a length direction, a first inductive coilstructure provided to enclose the dielectric tube and to produce ICP inthe dielectric tube, an RF power supply configured to provide positiveand negative powers having opposite phases, to respectively supplypositive and negative powers of RF power to both ends of the firstinductive coil structure, and to change a driving frequency, a firstmain capacitor provided between a positive output terminal of the RFpower supply and one end of the first inductive coil structure, and asecond main capacitor provided between a negative output terminal of theRF power supply and an opposite end of the first inductive coilstructure. The first inductive coil structure may include inductivecoils connected in series to each other and placed at different layers,the inductive coils having at least one turn at each layer, andauxiliary capacitors, which are respectively provided between adjacentones of the inductive coils to distribute a voltage applied to theinductive coils.

In some embodiments, each of the inductive coils may have the sameinductance of first inductance L1, each of the auxiliary capacitors mayhave the same capacitance of first capacitance C1, and a drivingfrequency of the RF power may be controlled to coincide with a resonancefrequency, which is determined by the first inductance L1 and the firstcapacitance C1 connected in series to each other.

In some embodiments, each of the first main capacitor and the secondmain capacitor may have the same capacitance of second capacitance C2,and the second capacitance C2 may be two times the first capacitance C1.

In some embodiments, each of the inductive coils may be a 2- to 4-turnantenna.

In some embodiments, the ICP generation system may further include asecond inductive coil structure provided to enclose the dielectric tube,to produce ICP in the dielectric tube, and to have the same structure asthe first inductive coil structure, the second inductive coil structurebeing spaced apart from the first inductive coil structure. One end ofthe second inductive coil structure may be connected to one end of thefirst inductive coil structure, an opposite end of the second inductivecoil structure may be connected to an opposite end of the firstinductive coil structure, and the first inductive coil structure and thesecond inductive coil structure may be connected in parallel to eachother between the first main capacitor and the second main capacitor.

In some embodiments, each of the inductive coils constituting the firstinductive coil structure and the second inductive coil structure mayhave the same inductance of first inductance L1, each of the auxiliarycapacitors constituting the first inductive coil structure and thesecond inductive coil structure may have the same capacitance of firstcapacitance C1, and a driving frequency of the RF power may becontrolled to coincide with a resonance frequency, which is determinedby the first inductance L1 and the first capacitance C1 connected inseries to each other.

In some embodiments, each of the first main capacitor and the secondmain capacitor may have the same capacitance of second capacitance C2,and the second capacitance C2 may be four times the first capacitanceC1.

In some embodiments, the one end of the first inductive coil structureand the one end of the second inductive coil structure may be placed tobe adjacent to each other, and the one end of the first inductive coilstructure and the one end of the second inductive coil structure may beconnected to each other and may be connected to the first maincapacitor.

In some embodiments, each of the inductive coils may include a firstcircular arc portion, which has a portion opened in a first direction ina rectangular coordinate system and is provided on an arrangement planeto have a first central angle and a constant first radius, a secondcircular arc portion, which is provided on the arrangement plane to havea second central angle less than the first central angle, to have asecond radius larger than the first radius, and to have the same centeraxis as a center axis of the first circular arc portion, a firstconnecting portion, which is provided on the arrangement plane to beconnected to one end of the first circular arc portion and to extend inthe first direction, a “U”-shaped first circular arc connecting portion,which is provided on the arrangement plane to connect an opposite end ofthe first circular arc portion with one end of the second circular arcportion, and a second connecting portion, which is provided on thearrangement plane to be connected to an opposite end of the secondcircular arc portion and to extend in the first direction.

In some embodiments, each of the inductive coils may include a firstcircular arc portion, which has a portion opened in a first direction ina rectangular coordinate system and is provided on an arrangement planeto have a first central angle and a constant first radius, a secondcircular arc portion, which is provided on the arrangement plane to havea second central angle less than the first central angle, to have asecond radius larger than the first radius, and to have the same centeraxis as a center axis of the first circular arc portion, a thirdcircular arc portion, which is provided on the arrangement plane to havea third central angle less than the second central angle, to have athird radius larger than the second radius, and to have the same centeraxis as the center axis of the first circular arc portion, a firstconnecting portion, which is provided on the arrangement plane to beconnected to one end of the first circular arc portion and to extend inthe first direction, a “U”-shaped first circular arc connecting portion,which is provided on the arrangement plane to connect an opposite end ofthe first circular arc portion with one end of the second circular arcportion, a “U”-shaped second circular arc connecting portion, which isprovided on the arrangement plane to connect an opposite end of thesecond circular arc portion to one end of the third circular arcportion, and a second connecting portion, which is provided on thearrangement plane to be connected to an opposite end of the thirdcircular arc portion and to extend in the first direction.

In some embodiments, each of the inductive coils may include a firstcircular arc portion, which has a portion opened in a first direction ina rectangular coordinate system and is provided on an arrangement planeto have a first central angle and a constant first radius, a secondcircular arc portion, which is provided on the arrangement plane to havea second central angle less than the first central angle, to have asecond radius larger than the first radius, and to have the same centeraxis as a center axis of the first circular arc portion, a thirdcircular arc portion, which is provided on the arrangement plane to havea third central angle less than the second central angle, to have athird radius larger than the second radius, and to have the same centeraxis as the center axis of the first circular arc portion, a fourthcircular arc portion, which is provided on the arrangement plane to havea fourth central angle less than the third central angle, to have afourth radius larger than the third radius, and to have the same centeraxis as the center axis of the first circular arc portion, a firstconnecting portion, which is provided on the arrangement plane to beconnected to one end of the first circular arc portion and to extend inthe first direction, a “U”-shaped first circular arc connecting portion,which is provided on the arrangement plane to connect an opposite end ofthe first circular arc portion with one end of the second circular arcportion, a “U”-shaped second circular arc connecting portion, which isprovided on the arrangement plane to connect an opposite end of thesecond circular arc portion to one end of the third circular arcportion, a “U”-shaped third circular arc connecting portion, which isprovided on the arrangement plane to connect an opposite end of thethird circular arc portion to one end of the fourth circular arcportion, and a second connecting portion, which is provided on thearrangement plane to be connected to an opposite end of the fourthcircular arc portion and to extend in the first direction.

In some embodiments, the first inductive coil structure and the secondinductive coil structure may be provided to have a vertical mirrorsymmetry with reference to a point of the dielectric discharge tube, andcurrent may be vertically divided at a center and then may be collectedat both ends.

In some embodiments, power input terminals of the inductive coils may bearranged to maintain a uniform angle in an azimuth direction.

In some embodiments, at least a portion of the inductive coils may befixed by a ceramic mold.

In some embodiments, the ICP generation system may further include awasher-shaped insulating spacer, which is provided between the inductivecoils to electrically disconnect the inductive coils from each other.

In some embodiments, the inductive coils may include first to fourthinductive coils sequentially stacked, and the auxiliary capacitor mayinclude first to third auxiliary capacitors. When compared with thefirst inductive coil, the second inductive coil may be rotatedcounterclockwise by 90° and may be placed below and aligned with thefirst inductive coil. When compared with the second inductive coil, thethird inductive coil may be rotated counterclockwise by 90° and may beplaced below and aligned with the second inductive coil. When comparedwith the third inductive coil, the fourth inductive coil may be rotatedcounterclockwise by 90° and may be placed below and aligned with thethird inductive coil. One end of the first inductive coil may beconnected to a positive output terminal of the RF power supply throughthe first main capacitor, an opposite end of the first inductive coilmay be connected to one end of the second inductive coil through thefirst auxiliary capacitor, an opposite end of the second inductive coilmay be connected to one end of the third inductive coil through thesecond auxiliary capacitor, an opposite end of the third inductive coilmay be connected to one end of the fourth inductive coil through thethird auxiliary capacitor, and an opposite end of the fourth inductivecoil may be connected to a negative output terminal of the RF powersupply through the second main capacitor.

According to some embodiments of the inventive concept, a substrateprocessing system may include a process chamber configured to process asemiconductor substrate, and an ICP generation system configured toprovide active species, which are provided by plasma, into the processchamber. The ICP generation system may include a dielectric tubeextending in a length direction, a first inductive coil structureprovided to enclose the dielectric tube and to produce ICP in thedielectric tube, an RF power supply configured to provide positive andnegative powers having opposite phases, to respectively supply positiveand negative powers of RF power to both ends of the first inductive coilstructure, and to change a driving frequency, a first main capacitorprovided between a positive output terminal of the RF power supply andone end of the first inductive coil structure, and a second maincapacitor provided between a negative output terminal of the RF powersupply and an opposite end of the first inductive coil structure. Thefirst inductive coil structure may include inductive coils connected inseries to each other and placed at different layers, the inductive coilshaving at least one turn at each layer, and auxiliary capacitors, whichare respectively provided between adjacent ones of the inductive coilsto distribute a voltage applied to the inductive coils.

According to some embodiments of the inventive concept, an inductivecoil structure may be provided to enclose a dielectric tube and toproduce ICP in the dielectric tube. The inductive coil structure mayinclude inductive coils connected in series to each other and placed atdifferent layers, the inductive coils having at least one turn at eachlayer and having the same structure, and auxiliary capacitors, which arerespectively provided between adjacent ones of the inductive coils todistribute a voltage applied to the inductive coils.

In some embodiments, each of the inductive coils may include a firstcircular arc portion, which has a portion opened in a first direction ina rectangular coordinate system and may be provided on an arrangementplane to have a first central angle and a constant first radius, asecond circular arc portion, which is provided on the arrangement planeto have a second central angle less than the first central angle, tohave a second radius larger than the first radius, and to have the samecenter axis as a center axis of the first circular arc portion, a thirdcircular arc portion, which is provided on the arrangement plane to havea third central angle less than the second central angle, to have athird radius larger than the second radius, and to have the same centeraxis as the center axis of the first circular arc portion, a firstconnecting portion, which is provided on the arrangement plane to beconnected to one end of the first circular arc portion and to extend inthe first direction, a “U”-shaped first circular arc connecting portion,which is provided on the arrangement plane to connect an opposite end ofthe first circular arc portion with one end of the second circular arcportion, a “U”-shaped second circular arc connecting portion, which isprovided on the arrangement plane to connect an opposite end of thesecond circular arc portion to one end of the third circular arcportion, a second connecting portion, which is provided on thearrangement plane to be connected to an opposite end of the thirdcircular arc portion and to extend in the first direction.

In some embodiments, each of the inductive coils may include a firstcircular arc portion, which has a portion opened in a first direction ina rectangular coordinate system and is provided on an arrangement planeto have a first central angle and a constant first radius, a secondcircular arc portion, which is provided on the arrangement plane to havea second central angle less than the first central angle, to have asecond radius larger than the first radius, and to have the same centeraxis as a center axis of the first circular arc portion, a thirdcircular arc portion, which is provided on the arrangement plane to havea third central angle less than the second central angle, to have athird radius larger than the second radius, and to have the same centeraxis as the center axis of the first circular arc portion, a fourthcircular arc portion, which is provided on the arrangement plane to havea fourth central angle less than the third central angle, to have afourth radius larger than the third radius, and to have the same centeraxis as the center axis of the first circular arc portion, a firstconnecting portion, which is provided on the arrangement plane to beconnected to one end of the first circular arc portion and to extend inthe first direction, a “U”-shaped first circular arc connecting portion,which is provided on the arrangement plane to connect an opposite end ofthe first circular arc portion with one end of the second circular arcportion, a “U”-shaped second circular arc connecting portion, which isprovided on the arrangement plane to connect an opposite end of thesecond circular arc portion to one end of the third circular arcportion, a “U”-shaped third circular arc connecting portion, which isprovided on the arrangement plane to connect an opposite end of thethird circular arc portion to one end of the fourth circular arcportion, and a second connecting portion, which is provided on thearrangement plane to be connected to an opposite end of the fourthcircular arc portion and to extend in the first direction.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will be more clearly understood from the followingbrief description taken in conjunction with the accompanying, exampledrawings. The accompanying drawings represent non-limiting, exampleembodiments as described herein.

FIG. 1 is a conceptual diagram illustrating a semiconductor substrateprocessing system according to example embodiments of the inventiveconcept.

FIG. 2A is a conceptual diagram illustrating an ICP generation systemaccording to example embodiments of the inventive concept.

FIG. 2B is a circuit diagram illustrating the ICP generation system ofFIG. 2A.

FIG. 2C is a diagram illustrating voltage division in the ICP generationsystem of FIG. 2A.

FIG. 2D is a plan view illustrating the ICP generation system of FIG.2A.

FIG. 2E is a plan view illustrating an inductive coil of the ICPgeneration system of FIG. 2A.

FIG. 3A is a conceptual diagram illustrating an ICP generation systemaccording to other example embodiments of the inventive concept.

FIG. 3B is a circuit diagram illustrating the ICP generation system ofFIG. 3A.

FIG. 3C is a diagram illustrating a voltage division in an inductivecoil structure of the ICP generation system of FIG. 3A.

FIG. 4A is a conceptual diagram illustrating an ICP generation systemaccording to still other example embodiments of the inventive concept.

FIG. 4B is a circuit diagram illustrating the ICP generation system ofFIG. 4A.

FIG. 4C is a diagram illustrating voltage division in an inductive coilstructure of the ICP generation system of FIG. 4A.

FIG. 4D is a plan view illustrating an inductive coil of the ICPgeneration system of FIG. 4A.

FIG. 5A is a conceptual diagram illustrating an ICP generation systemaccording to even other example embodiments of the inventive concept.

FIG. 5B is a plan view illustrating an inductive coil of the ICPgeneration system of FIG. 5A.

It should be noted that these figures are intended to illustrate thegeneral characteristics of methods, structure and/or materials utilizedin certain example embodiments and to supplement the written descriptionprovided below. These drawings are not, however, to scale and may notprecisely reflect the precise structural or performance characteristicsof any given embodiment, and should not be interpreted as defining orlimiting the range of values or properties encompassed by exampleembodiments. For example, the relative thicknesses and positioning ofmolecules, layers, regions and/or structural elements may be reduced orexaggerated for clarity. The use of similar or identical referencenumbers in the various drawings is intended to indicate the presence ofa similar or identical element or feature.

DETAILED DESCRIPTION

In an antenna provided to surround a dielectric discharge tube, highvoltage electric potential (3 kV or higher) is applied in the dielectricdischarge tube under the condition of low pressure (lower than severaltens of Torr without fluid effects). In this case, plasma is generatedin the dielectric discharge tube. A surface of the dielectric dischargetube is heated by collision of ions. Accordingly, the dielectricdischarge tube is heated to a temperature of 1000° C. or higher. Thismay lead to a change in surface characteristics of the dielectricdischarge tube or perforation of the dielectric discharge tube.

The high electric potential applied to the antenna is affected byinductance, frequency, and current of the antenna. In the high powercondition, a high electric potential is necessarily applied to theantenna. Thus, it is necessary to lower the high electric potential inthe antenna.

According to some embodiments of the inventive concept, in the casewhere the high power of several kW or higher is applied, a method oflowering the applied high voltage and of minimizing a heating issue byion collision is proposed.

The inductively-coupled plasma (ICP) system may be used for asemiconductor processing apparatus, an inductively coupled spectralanalysis apparatus, an ion beam generating apparatus, an apparatus forcleaning a deposition chamber, an apparatus for cleaning an exhaust holeof a deposition chamber, a plasma scrubber for removing waste gas from asemiconductor processing apparatus, or a cleaning apparatus for cleaninga process chamber of a chemical vapor deposition system.

In some embodiments, an ICP generation system may be used as a remoteplasma source providing active species into a semiconductor processingchamber.

An inductive coil generating the ICP and plasma may be modeled as atransformer circuit. Accordingly, the ICP is called “transformer coupledplasma”. The inductive coil serves as a primary coil of the transformercircuit, and the plasma serves as a secondary coil of the transformercircuit. A magnetic flux confinement material such as a magneticmaterial may be used to increase a magnetic coupling between theinductive coil and the plasma. However, it is difficult to apply themagnetic flux confinement material to a cylindrical dielectric dischargecontainer. Another method for enhancing the magnetic coupling betweenthe inductive coil and the plasma is to increase inductance or windingnumber of inductive coil. However, the increase in inductance of theinductive coil increases impedance and makes it difficult to transmitthe power efficiently. In addition, the increase in inductance of theinductive coil may increase voltage to be applied to the inductive coil,thereby causing parasitic arc discharge. Also, high voltage applied tothe inductive coil may lead to capacitively-coupled discharge and thedamage of the dielectric discharge container by ion collision and heat.

According to some embodiments of the inventive concept, a capacitor maybe provided between series-connected inductive coils, and this makes itpossible to reduce the voltage applied to the inductive coil and allowsthe overall voltage to be distributed between the inductive coil and thecapacitor. In detail, the inductive coil may be divided into a pluralityof inductive coils, auxiliary capacitors may be provided between thedivided inductive coils, and main capacitors may be provided at bothends of the inductive coil. In this case, the electrostatic field may bereduced by the screening effect, and according to the voltagedistribution model, the voltage applied to the inductive coil may bereduced. The divided inductive coils and the auxiliary capacitorstherebetween may constitute a series resonant circuit, and the resonancecircuit may be configured to have the same resonance frequency as thedriving frequency of the AC power supply. Accordingly, even when a lowvoltage is applied to the inductive coil, the impedance matchingoperation can be performed stably.

Inductively coupled plasma is generated using a driving frequency ofseveral MHz, typically at a pressure of hundreds of mTorr. However,since the inductive electric field is weak, it is difficult to use theICP for the discharge at atmospheric pressure or at high pressure ofseveral Torr or higher. Accordingly, it is necessary to sufficientlyincrease the strength of the induced electric field and to provide anadditional component for an initial discharge.

In the case where an ICP discharge is performed by applying RF power tothe inductive coil surrounding the dielectric tube, the dielectric tubemay be heated and damaged by the ICP. That is, the ICP has a structurallimitation at high power of several tens of kWatt or higher.

In some embodiments, in order to improve the efficiency or stability ofconventional ICPs, 1) an antenna (or a coil structure) is provided in astacked form, thereby increasing an intensity of an inductive electricfield, 2) an inductive coil is divided into a plurality of inductivecoils and a capacitor for reducing impedance is disposed between theinductive coils, 3) main capacitors are connected to both ends of theinductive coil to satisfy the overall resonance condition, and 4) afrequency-varying AC power part is provided to improve plasma stabilityof the inductive coil. Thus, it is possible to perform a process at aflow rate of several tens to several hundreds of liters per minute andat a high pressure of several Torr or higher, which cannot be realizedby the conventional ICP generation system. In addition, there is no needfor an additional electrode for the initial discharge, and the initiallydischarge may be performed even when the driving frequency of the ACpower part does not satisfy the resonance condition. In the case wherethe resonance condition is not satisfied, high voltage is applied to theinductive coil to perform the initial discharge, and then, a maindischarge is performed by changing the driving frequency of the AC powerpart to the resonance condition.

The terms “inductive coil” and “antenna” are used interchangeably in thefollowing. For an ICP antenna, an intensity of inductive electric fieldtransmitted to the plasma is proportional to a current and frequency ofthe inductive coil and proportional to square of a winding number.Therefore, by increasing the winding number of the inductive coil orantenna, it may be possible to apply a strong electric field to theplasma. However, if the winding number of a solenoid coil increases,energy is dispersed in a length direction of the dielectric dischargetube, due to spatial constraint. In addition, the high inductance(impedance) of the inductive coil makes it difficult to transfer powerfrom the RF power generator to the inductive coil or the antenna.

It is necessary to increase the density of the electric field near theplasma, and thus, it is necessary to maximize the number of windings perunit length in the length direction of the dielectric discharge tube. Inthe case where a high voltage is applied to the inductive coil, theinductive coil generates a capacitively coupled plasma reducingstability of the discharge. The capacitively coupled plasma isadvantageous for the initial discharge, but since it causes ionacceleration, a dielectric tube or a dielectric window, through which aninductive electric field is transmitted, may be damaged.

In some embodiments, to solve the damage problem of the dielectricdischarge tube due to the high voltage applied to the antenna,capacitors may be interposed between antennas placed in each layer.Thus, even if more power is applied to the antenna, the dielectricdischarge tube may not be damaged. The capacitor may be used between theunit antennas to lower a voltage applied to the antenna. In addition, itmay be possible to suppress a parasitic discharge, owing to a highvoltage between the antenna and a power input terminal and between theantenna and a power output terminal.

If the high voltage is applied to the antenna, it may lead toacceleration and collision of ions, and the surface may be heated tohigh temperature and may be damaged. Owing to these problems, it isdifficult to apply the high power condition to the ICP, andalternatively, methods of reducing inductance or spacing the antennaaway from the tube are used.

In some embodiments, in the case where capacitors are placed in seriesbetween the unit antennas constituting the antenna, the highest electricpotential may be reduced in inverse proportion to the division number ofthe unit antennas, and the damage of the dielectric discharge tube maybe reduced even at high power.

According to a comparative example, antennas with the same inductancewere tested. The capacitor was not applied to one of the antennas, butin the other of the antennas, the capacitor was placed in series betweenthe unit antennas constituting the antenna. For the conventionalantenna, the dielectric discharge tube was damaged at the power of 2 kW.However, for the case according to the inventive concept, the dielectricdischarge tube was not damaged even at the power of 8 kW and providedimproved discharge characteristics. In detail, for the conventionalantenna, N₂ gas could not be injected at the power of 4 kW or lower, butfor the improved antenna, it was possible to inject from the power of1.5 kW.

Example embodiments of the inventive concept will now be described morefully with reference to the accompanying drawings, in which exampleembodiments are shown. Example embodiments of the inventive concept may,however, be embodied in many different forms and should not be construedas being limited to the embodiments set forth herein; rather, theseembodiments are provided so that this disclosure will be thorough andcomplete, and will fully convey the concept of example embodiments tothose of ordinary skill in the art. In the drawings, the thicknesses oflayers and regions are exaggerated for clarity. Like reference numeralsin the drawings denote like elements, and thus their description will beomitted.

FIG. 1 is a conceptual diagram illustrating a semiconductor substrateprocessing system according to example embodiments of the inventiveconcept.

Referring to FIG. 1, a semiconductor substrate processing system 2 mayinclude a process chamber 92, which is used to process a substrate 94,and an ICP generation system 100, which is configured to provide activespecies produced by an inductively-coupled plasma into the processchamber.

The process chamber 92 may be configured to deposit a thin film (e.g., atungsten layer) on the substrate 94. The process chamber 92 may beconfigured to receive a first process gas (e.g., WF₆) and the activespecies (e.g., hydrogen active species) from the ICP generation system100. The active species may be produced from hydrogen (H₂) plasma. Theprocess chamber 92 may include a gas distributing part 91. The gasdistributing part 91 may be configured to receive the first process gasfrom a process gas supplying part 96 and the active species from the ICPgeneration system 100. To uniformly deposit a thin film on thesubstrate, the gas distributing part 91 may spatially distribute the gassupplied thereto.

The ICP generation system 100 may be a remote plasma source. The ICPgeneration system 100 may be configured to produce hydrogen plasma withhigh efficiency, under a high pressure of several Torr. The ICPgeneration system 100 may include an inductive discharge module 191 andan RF power supply 140, which is configured to supply an electric powerto the inductive discharge module 101. The ICP generation system 100 maybe configured to receive a second process gas, to produce active speciesfrom the second process gas using ICP, and to provide the active speciesto the process chamber 92.

A substrate holder 93 may be provided in the process chamber 92 to faceand be parallel to the gas distributing part 91, and the substrate 94may be provided on the substrate holder 93 and in the process chamber92. The substrate holder 93 may be heated, for a chemical vapordeposition process. The substrate 94 may be a semiconductor substrate.In detail, the substrate may be a silicon wafer. A vacuum pump 95 may beprovided to exhaust gas from the process chamber 92.

In certain embodiments, the active species may be directly supplied tothe process chamber 92, not through the gas distributing part 91.

In certain embodiments, the semiconductor substrate processing system 2is not limited to be used for the chemical vapor deposition process, andthe semiconductor substrate processing system 2 may be used to performvarious processes.

In certain embodiments, the ICP generation system 100 is not limited tobe used for the chemical vapor deposition process and may be used for aprocess of cleaning the process chamber 92. For example, thesemiconductor substrate processing system 2 may include an additionalremote plasma source, which is configured to discharge NF₃ and toperform a cleaning process on the process chamber 92. In this case,since fluorine leads to a change in process environment of the processchamber 92, the ICP generation system 100 may provide the hydrogenactive species to the process chamber 92. Accordingly, fluorine adsorbedon an inner surface of the process chamber 92 may be reacted with thehydrogen active species and may be removed.

FIG. 2A is a conceptual diagram illustrating an ICP generation systemaccording to example embodiments of the inventive concept.

FIG. 2B is a circuit diagram illustrating the ICP generation system ofFIG. 2A.

FIG. 2C is a diagram illustrating voltage division in the ICP generationsystem of FIG. 2A.

FIG. 2D is a plan view illustrating the ICP generation system of FIG.2A.

FIG. 2E is a plan view illustrating an inductive coil of the ICPgeneration system of FIG. 2A.

Referring to FIGS. 2A through 2E, the ICP generation system 100 mayinclude a dielectric tube 130 extending in a length direction; a firstinductive coil structure 110, which is provided to enclose thedielectric tube 130 and to produce ICP in the dielectric tube 130; an RFpower supply 140, which is configured to provide positive and negativepowers having opposite phases, to respectively supply positive andnegative powers of RF power to both ends of the first inductive coilstructure, and to change a driving frequency; a first main capacitor 121provided between a positive output terminal of the RF power supply andone end of the first inductive coil structure; and a second maincapacitor 122 provided between a negative output terminal of the RFpower supply and an opposite end of the first inductive coil structure.

The first inductive coil structure 110 may include inductive coils 112,114, 116, and 118, which are connected in series to each other and areplaced at different layers, and auxiliary capacitors 113, 115, and 117,which are respectively provided between adjacent ones of the inductivecoils to distribute a voltage applied to the inductive coils. Theinductive coils 112, 114, 116, and 118 may be provided to have at leastone turn at each layer.

The driving frequency of the RF power supply 140 may range from severalhundreds of kHz to several MHz. An output power of the RF power supply140 may range from several tens of watts to several tens of kW. The RFpower supply 140 may supply an electric power to a time-varying load(ICP) through the first inductive coil structure. The inductive coil ofthe first inductive coil structure 110 may be electromagneticallycoupled with the ICP. Accordingly, an apparatus for impedance matchingbetween the RF power supply 140 and the first inductive coil structure110 may be required. The RF power supply 140 may be configured to outputa first output power and a second output power whose phases are oppositeto each other. At a certain time, the first output power and the secondoutput power may have opposite phases with respect to the ground.

A conventional impedance matching network may include two variablereactance devices (e.g., vacuum variable capacitors) or transformers forthe impedance matching. In this case, the first inductive coil structure110 may have a difficulty in stably meeting resonance condition with thedriving frequency. Thus, a RF power with a variable driving frequencymay be used to allow a pair of the inductive coil and the auxiliarycapacitor, which are adjacent to each other in the first inductive coilstructure, to meet a series resonance condition.

The dielectric tube 130 may have a cylindrical shape and may extend in alength direction. The dielectric tube 130 may be formed of a material(e.g., glass, quartz, ceramic, alumina, or sapphire) having a goodheat-resistance property. An inner diameter of the dielectric tube 130may be several tens of millimeters. A length of the dielectric tube 130may be several tens of centimeters.

A cylindrical ICP generation system may include a cylindrical dielectricdischarge tube and an antenna provided to surround the discharge tube.In the cylindrical ICP, an inductive electric field may not bevertically incident into the dielectric discharge tube, and thus, it maybe possible to reduce damage caused by ion impact. The cylindrical ICPmay produce an inductive electric field in a direction of a center axisof the cylindrical dielectric discharge tube. However, if the antenna isapplied with a high voltage, the antenna may producecapacitively-coupled plasma to heat the dielectric tube. Accordingly, anovel inductive coil structure is required to prevent high voltage frombeing applied to the antenna.

In the first inductive coil structure 110, the inductive electric fieldmay depend on the driving frequency and a current (or the number ofturns per unit length). Also, the highest voltage to be applied to thefirst inductive coil structure 110 may be determined depending on thetotal impedance and current of the first inductive coil structure 110.Impedance of the first inductive coil structure 110 may depend on theinductance and the driving frequency of the first inductive coilstructure 110. Accordingly, if the inductance of the first inductivecoil structure is increased to reduce the highest voltage to be appliedto the first inductive coil structure, the inductive electric field mayhave an increased strength, but a capacitive coupling effect may beincreased by the highest voltage. Thus, to reduce the impedance of thefirst inductive coil structure, the first inductive coil structure 10may include a plurality of inductive coils 112, 114, 116, and 118 and aplurality of auxiliary capacitors 113, 115, and 117, each of which isinterposed between adjacent ones of the inductive coils. Furthermore,the inductive coil and the auxiliary capacitor adjacent thereto may beconnected in series to each other to form a series resonance circuit.The inductive coils and the auxiliary capacitors may be electrically andalternately arranged and may be connected in series to each other.Accordingly, the first inductive coil structure may provide an overalllow impedance. The number of the auxiliary capacitors may be less by onethan the number of the inductive coils.

In addition, the first inductive coil structure 110 may constitute aperfect resonance circuit overall. For this, the first main capacitor121 may be connected to one end of the first inductive coil structure110, and the second main capacitor 122 may be connected to an oppositeend of the first inductive coil structure 110. To realize the perfectresonance circuit, capacitance C2 of the first main capacitor 121 may betwo times capacitance C1 of the auxiliary capacitor (i.e., C2=2C1).

If such a resonance circuit is configured, the highest voltage to beapplied to the first inductive coil structure 110 may be inverselyproportional to the number of the inductive coils.

The first inductive coil structure 110 may include inductive coils 112,114, 116, and 118, which are connected in series to each other and areplaced at different layers, and auxiliary capacitors 113 and 115, whichare respectively provided between adjacent ones of the inductive coilsto distribute a voltage applied to the inductive coils. The inductivecoils 112, 114, 116, and 118 may be provided to have at least one turnat each layer.

The inductive coils may include first to fourth inductive coils 112,114, 116, and 118. The auxiliary capacitor may include first to thirdauxiliary capacitors 113, 115, and 117. All of the first to fourthinductive coils 112, 114, 116, and 118 may have the same inductance ofL1. All of the first to third auxiliary capacitors 113, 115, and 117 mayhave the same capacitance of C1. Each of the first to third auxiliarycapacitors 113, 115, and 117 may have 2C1 and thus it may be depicted asa pair of serially-connected imaginary capacitors. Accordingly, thefirst main capacitor 121, the first inductive coil 112, and theimaginary capacitor may constitute a resonance circuit, thereby reducingthe voltage overall.

When compared with the case in which the auxiliary capacitors 113, 115,and 117 are not provided, if the auxiliary capacitors are provided, thevoltage may be decreased in inverse proportion to the number of theinductive coil. Nevertheless, the overall number of turns per unitlength in the dielectric tube may be maintained. To meet such aresonance condition, the driving frequency may be controlled to coincidewith the resonance frequency.

In addition, to increase the number of turns per unit length in thedielectric tube and thereby to increase the strength of the inductiveelectric field, each of the inductive coils 112, 114, 116, and 118 maybe a 3-turn coil or a 4-turn coil. The inductive coils 112, 114, 116,and 118 may be vertically stacked with a sufficiently small distance,and a space for electric connection may be required. To satisfy thisrequirement, each inductive coil may not have a portion jumping anarrangement plane, and input and output terminals of each inductive coilshould not be placed at a mutually-stacked position. For this, theinductive coil having the following structure is proposed.

The inductive coils 112, 114, 116, and 118 may include first to fourthinductive coils 112, 114, 116, and 118, which are sequentially stacked.The auxiliary capacitors 113, 115, and 117 may include first to thirdauxiliary capacitors 113, 115, and 117.

The auxiliary capacitor between each pair of the inductive coils may beconfigured to reverse the electric potential. In other words, on thesame arrangement plane, a turn (or a first circular arc portion) closeto the dielectric tube and the farthest turn (or a fourth circular arcportion) may be induced to have electric potentials opposite to eachother. In the dielectric tube, the electric potential of the inductivecoil may be canceled, and thus, an electrostatic electric field towardthe dielectric tube by a capacitive-coupling may not occur. Thisreduction of the electrostatic electric field may reduce a capacitivecoupling effect.

In a conventional structure, inductance may cause a large potentialdifference at both ends of an antenna, and the large potentialdifference may result in ion acceleration, energy loss, and heating anddamage of the dielectric tube. By contrast, in the case where theauxiliary capacitor is provided between the inductive coils, a potentialdifference may be reduced and the electric potential may have oppositesigns at internal and outer regions of each inductive coil. The electricpotentials having opposite signs may act as a dipole field in thedielectric tube, thereby reducing an electrostatic electric field. Eachof the inductive coils 112, 114, 116, and 118 may include a plurality ofwinding wires, which are wound outward on the same plane.

The first inductive coil 112 may be provided to surround the dielectrictube. When compared with the first inductive coil 112, the secondinductive coil 114 may be rotated counterclockwise by 90° and may beplaced below and aligned with the first inductive coil 112. Whencompared with the second inductive coil 114, the third inductive coil116 may be rotated counterclockwise by 90° and may be placed below andaligned with the second inductive coil 114. When compared with the thirdinductive coil 116, the fourth inductive coil 118 may be rotatedcounterclockwise by 90° and may be placed below and aligned with thethird inductive coil 116. One end of the first inductive coil 112 may beconnected to the positive output terminal of the RF power supply 140through the first main capacitor 121. An opposite end of the firstinductive coil 112 may be connected to one end of the second inductivecoil 114 through the first auxiliary capacitor 113. An opposite end ofthe second inductive coil 114 may be connected to one end of the thirdinductive coil 116 through the second auxiliary capacitor 115. Anopposite end of the third inductive coil 116 may be connected to one endof the fourth inductive coil 118 through the third auxiliary capacitor117. An opposite end of the fourth inductive coil 118 may be connectedto the negative output terminal of the RF power supply 140 through thesecond main capacitor 122. To maintain the azimuthal symmetry, each ofthe first to fourth inductive coils may be rotated by 90°, when it isstacked on another.

A voltage (e.g., 2V) of the innermost winding wire of each of inductivecoils may have a phase opposite to a voltage (e.g., −2V) of theoutermost winding wire. In addition, the innermost winding wires of allinductive coils may have the same voltage. Accordingly, parasiticcapacitance between adjacent ones of the inductive coils may be reducedand a discharge property may be improved. In addition, since plasma inthe dielectric tube is affected by the same voltage of the inner windingwires, a local ion sputtering may be reduced.

The inductive coil may be divided into a plurality of inductive coils,and auxiliary capacitors may be interposed between the divided inductivecoils to reduce the highest voltage. However, to provide a sufficientlyhigh inductive electric field, it is necessary to increase the number ofturns per unit length. To increase the number of turns per unit length,the number of turns in each of the inductive coils 112, 114, 116, and118 may be increased. However, it is necessary to dispose each inductivecoil on the same arrangement plane. If each inductive coil has a wiringportion that is not positioned on the arrangement plane, it may cause adifficult in densely stacking other inductive coils disposed on anadjacent layer. Each inductive coil may have 3 or 4 turns on the samearrangement plane.

In certain embodiments, the winding number of each inductive coil may beconfigured to have five or more turns.

Each of the inductive coils 112, 114, 116, and 118 may include a firstcircular arc portion 22 a, which has a portion opened in a first orx-axis direction in a rectangular coordinate system and is provided onan arrangement plane to have a first central angle and a constant firstradius; a second circular arc portion 22 b, which is provided on thearrangement plane to have a second central angle less than the firstcentral angle, to have a second radius larger than the first radius, andto have the same center axis as a center axis of the first circular arcportion; a third circular arc portion 22 c, which is provided on thearrangement plane to have a third central angle less than the secondcentral angle, to have a third radius larger than the second radius, andto have the same center axis as the center axis of the first circulararc portion; a fourth circular arc portion 22 d, which is provided onthe arrangement plane to have a fourth central angle less than the thirdcentral angle, to have a fourth radius larger than the third radius, andto have the same center axis as the center axis of the first circulararc portion; a first connecting portion 23 a, which is provided on thearrangement plane to be connected to one end of the first circular arcportion 22 a and to extend in the first or x-axis direction; a“U”-shaped first circular arc connecting portion 24 a, which is providedon the arrangement plane to connect an opposite end of the firstcircular arc portion 22 a with one end of the second circular arcportion 22 b; a “U”-shaped second circular arc connecting portion 24 b,which is provided on the arrangement plane to connect an opposite end ofthe second circular arc portion to one end of the third circular arcportion; a “U”-shaped third circular arc connecting portion 24 c, whichis provided on the arrangement plane to connect an opposite end of thethird circular arc portion to one end of the fourth circular arcportion; and a second connecting portion 23 b, which is provided on thearrangement plane to be connected to an opposite end of the fourthcircular arc portion 22 d and to extend in the first direction. Thefourth central angle may be equal to or greater than 270°. The firstcircular arc connecting portion 24 a, the second circular arc connectingportion 24 b, and the third circular arc connecting portion 24 c may beprovided in such a way that they are not overlapped with each other. Thefirst circular arc connecting portion 24 a may be provided in a regiondefined by the second circular arc connecting portion 24 b.

In each of the inductive coils 112, 114, 116, and 118, a space betweenwinding wires (e.g., the first to fourth circular arc portions) may beuniform. For example, the space may range from 1 mm to 3 mm. To allowthe inductive coil to have sufficient azimuthal symmetry, the first tofourth central angles may be equal to or greater than 270°. To suppressoccurrence of arc discharge at atmospheric pressure by a voltagedifference, the first to fourth circular arc portions may be spacedapart from each other by a sufficiently large distance of several mm orlarger.

Inductive coils provided at adjacent layers may be electricallydisconnected from each other by an insulating spacer 150. The insulatingspacer 150 may be provided in the form of a washer (e.g., a thincircular plate with central penetration hole) and may be inserted toenclose an outer side surface of the dielectric tube 130. The insulatingspacer 150 may be glass, plastic, or Teflon. A thickness of theinsulating spacer 150 may be of the order of several mm. An inner radiusof the insulating spacer 150 may be substantially equal to the outerradius of the dielectric tube 130, and an outer radius of the insulatingspacer 150 may be substantially equal to an outermost radius of theinductive coil. A distance between inner and outer radii of theinsulating spacer 150 may range from several to several tens of cm.

In some embodiments, at least a portion of the inductive coils 112, 114,116, and 118 may be molded by a ceramic paste. A ceramic mold 152encapsulating at least a portion of the inductive coil may be in thermalcontact with the dielectric tube 130. Accordingly, in the case wherethere is refrigerant flowing in the inductive coils 112, 114, 116, and118, the inductive coil may refrigerate the ceramic mold 152, and theceramic mold 152 may refrigerate indirectly the dielectric tube 130.

Each of the inductive coils 112, 114, 116, and 118 may be provided to beoutward wound around the dielectric tube four times at each layer. Apair of inductive coils placed at adjacent layers may be connected inseries to each other by an auxiliary capacitor therebetween. Theauxiliary capacitor may be provided to have capacitance canceling theinductance of the inductive coil. Four inductive coils may constituteone group. The four inductive coils may be arranged in such a way thateach of them is rotated counterclockwise by 90° with respect to aprevious one.

Both ends of the dielectric tube may be sealed by a flange. An upperflange 132 may fasten one end of the dielectric tube and may include anozzle 131 supplying a mixture gas of hydrogen and nitrogen. Theinductive coils 112, 114, 116, and 118 enclosing a center portion thedielectric tube may generate ICP in the dielectric tube. A lower flange134 may fasten an opposite end of the dielectric tube, and gas, whichcan be additionally decomposed by the ICP, may be provided to theopposite end of the dielectric tube.

FIG. 3A is a conceptual diagram illustrating an ICP generation systemaccording to other example embodiments of the inventive concept.

FIG. 3B is a circuit diagram illustrating the ICP generation system ofFIG. 3A.

FIG. 3C is a diagram illustrating a voltage division in an inductivecoil structure of the ICP generation system of FIG. 3A.

Referring to FIGS. 3A through 3C, an ICP generation system 200 mayinclude a dielectric tube 130 extending in a length direction; a firstinductive coil structure 110, which is provided to enclose thedielectric tube 130 and to produce ICP in the dielectric tube 130; an RFpower supply 140, which is configured to provide positive and negativepowers having opposite phases, to respectively supply positive andnegative powers of RF power to both ends of the first inductive coilstructure, and to change a driving frequency; a first main capacitor 121provided between a positive output terminal of the RF power supply andone end of the first inductive coil structure; and a second maincapacitor 122 provided between a negative output terminal of the RFpower supply and an opposite end of the first inductive coil structure.

A second inductive coil structure 210 may be provided to surround thedielectric tube 130 and may be spaced apart from the first inductivecoil structure 110 in the length direction. The second inductive coilstructure 210 may have the same structure as the first inductive coilstructure 110 and may be used to generate ICP in the dielectric tube130.

One end of the second inductive coil structure 210 may be connected tothe one end of the first inductive coil structure 110, and an oppositeend of the second inductive coil structure 210 may be connected to theopposite end of the first inductive coil structure 110. The firstinductive coil structure 110 and the second inductive coil structure 210may be connected in parallel to each other, between the first maincapacitor 121 and the second main capacitor 122.

Each of the inductive coils 112, 114, 116, and 118 constituting thefirst inductive coil structure 110 and the second inductive coilstructure 210 may have the same inductance (e.g., of first inductanceL1). Each of the auxiliary capacitors 113, 115, and 117 constituting thefirst inductive coil structure 110 and the second inductive coilstructure 210 may have the same capacitance of first capacitance C1. Adriving frequency of the RF power supply 140 may be controlled tocoincide with a resonance frequency, which is determined by the firstinductance L1 and the first capacitance C1 connected in series to eachother.

The first main capacitor and the second main capacitor may have the samecapacitance (e.g., of second capacitance C2), and the second capacitanceC2 may be four times the first capacitance C1.

The one end of the first inductive coil structure 110 may be disposedadjacent to the one end of the second inductive coil structure 210. Theone end of the first inductive coil structure and the one end of thesecond inductive coil structure may be connected to each other and maybe connected to the first main capacitor 121. The opposite end of thefirst inductive coil structure 110 and the opposite end of the secondinductive coil structure 210 may be connected to each other and may beconnected to the second main capacitor.

The first inductive coil structure 110 and the second inductive coilstructure 210 may be provided to have a vertical mirror symmetry withreference to a point of the dielectric discharge tube 130. Current maybe vertically divided at a center and then may be collected at bothends.

In addition, the first inductive coil structure 110 and the secondinductive coil structure 210 may constitute a perfect resonance circuitoverall. For this, the first main capacitor 121 may be connected to theone end of the first inductive coil structure 110 and the one end of thesecond inductive coil structure 210. The second main capacitor 122 maybe connected to the opposite end of the first inductive coil structure110 and the opposite end of the second inductive coil structure 210. Torealize the perfect resonance circuit, capacitance C2 of the first maincapacitor 121 may be four times capacitance C1 of the auxiliarycapacitor (i.e., C2=4C1). The first main capacitor may be depicted as aparallel-connected capacitor and may have 2C1.

The inductive coils may include first to fourth inductive coils 112,114, 116, and 118. The auxiliary capacitor may include first to thirdauxiliary capacitors 113, 115, and 117. All of the first to fourthinductive coils 112, 114, 116, and 118 may have the same inductance ofL1. All of the first to third auxiliary capacitors 113, 115, and 117 mayhave the same capacitance of C1. Each of the first to third auxiliarycapacitors 113, 115, and 117 may be depicted as a pair ofserially-connected imaginary capacitors and may have 2C1. Accordingly, aportion (2C1) of the first main capacitor 121, the first inductive coil112, and the imaginary capacitor (2C1) may constitute a resonancecircuit, thereby reducing the voltage overall.

The first inductive coil structure 110 and the second inductive coilstructure 210 may be connected in parallel to each other, and thus, theICP generation system 200 may include eight inductive coils. Theinductive coils of the first inductive coil structure may besequentially arranged in such a way that each of them is rotatedcounterclockwise by 90° with respect to a previous one. The inductivecoils of the second inductive coil structure may be sequentiallyarranged in such a way that each of them is rotated clockwise by 90°with respect to a previous one.

The auxiliary capacitor may be provided to cancel an imaginary part ofimpedance between the inductive coils. Both ends of two groups (i.e.,the first and second inductive coil structures), each of which includesfour serially-connected inductive coils, may be connected in parallel toeach other and then may be electrically connected to an outer terminal.

The auxiliary capacitor between each pair of the inductive coils may beconfigured to reverse the electric potential. In other words, on thesame arrangement plane, the innermost turn (or a first circular arcportion) close to the dielectric tube and the outermost turn (or afourth circular arc portion) may be induced to have electric potentialsopposite to each other. In the dielectric tube, the electric potentialof the inductive coil may be canceled, and thus, an electrostaticelectric field toward the dielectric tube by a capacitive-coupling maynot occur. This reduction of the electrostatic electric field may reducea capacitive coupling effect.

In a conventional structure, inductance may cause a large potentialdifference at both ends of an antenna, and the large potentialdifference may result in ion acceleration, energy loss, and heating anddamage of the dielectric tube. By contrast, in the case where theauxiliary capacitor is provided between the inductive coils, a potentialdifference may be reduced and the electric potential may have oppositesigns at internal and outer regions of each inductive coil. The electricpotentials having opposite signs may act as a dipole field in thedielectric tube, thereby reducing an electrostatic electric field.

FIG. 4A is a conceptual diagram illustrating an ICP generation systemaccording to still other example embodiments of the inventive concept.

FIG. 4B is a circuit diagram illustrating the ICP generation system ofFIG. 4A.

FIG. 4C is a diagram illustrating voltage division in an inductive coilstructure of the ICP generation system of FIG. 4A.

FIG. 4D is a plan view illustrating an inductive coil of the ICPgeneration system of FIG. 4A.

Referring to FIGS. 4A through 4D, an ICP generation system 300 mayinclude a dielectric tube 130 extending in a length direction; a firstinductive coil structure 310, which is provided to enclose thedielectric tube 130 and to produce ICP in the dielectric tube 130; an RFpower supply 140, which is configured to provide positive and negativepowers having opposite phases, to respectively supply positive andnegative powers of RF power to both ends of the first inductive coilstructure, and to change a driving frequency; a first main capacitor 121provided between a positive output terminal of the RF power supply andone end of the first inductive coil structure; and a second maincapacitor 122 provided between a negative output terminal of the RFpower supply and an opposite end of the first inductive coil structure.

the first main capacitor 121 and the second main capacitor 122 may havethe same capacitance (e.g., of second capacitance C2), and the secondcapacitance C2 may be two times the first capacitance C1 of theauxiliary capacitor.

Inductive coils may include first to fourth inductive coils 312, 314,316, and 318. The auxiliary capacitor may include first to thirdauxiliary capacitors 113, 115, and 117. All of the first to fourthinductive coils 312, 314, 316, and 318 may have the same inductance ofL1. All of the first to third auxiliary capacitors 113, 115, and 117 mayhave the same capacitance of C1. Each of the first to third auxiliarycapacitors 113, 115, and 117 may be depicted as a pair ofserially-connected imaginary capacitors and may have 2C1. Accordingly, aportion (2C1) of the first main capacitor 121, the first inductive coil312, and the imaginary capacitor (2C1) may constitute a resonancecircuit, thereby reducing the voltage overall.

Each of the inductive coils 312, 314, 316, and 318 may include a firstcircular arc portion 32 a, which has a portion opened in a first orx-axis direction in a rectangular coordinate system and is provided onan arrangement plane to have a first central angle and a constant firstradius; a second circular arc portion 32 b, which is provided on thearrangement plane to have a second central angle less than the firstcentral angle, to have a second radius larger than the first radius, andto have the same center axis as a center axis of the first circular arcportion; a third circular arc portion 32 c , which is provided on thearrangement plane to have a third central angle less than the secondcentral angle, to have a third radius larger than the second radius, andto have the same center axis as the center axis of the first circulararc portion; a first connecting portion 33 a, which is provided on thearrangement plane to be connected to one end of the first circular arcportion and to extend in the first direction; a “U”-shaped firstcircular arc connecting portion 34 a, which is provided on thearrangement plane to connect an opposite end of the first circular arcportion to one end of the second circular arc portion; a “U”-shapedsecond circular arc connecting portion 34 b, which is provided on thearrangement plane to connect an opposite end of the second circular arcportion to one end of the third circular arc portion; and a secondconnecting portion 33 b, which is provided on the arrangement plane tobe connected to an opposite end of the third circular arc portion and toextend in the first direction. The third central angle may be equal toor greater than 270°.

FIG. 5A is a conceptual diagram illustrating an ICP generation systemaccording to even other example embodiments of the inventive concept.

FIG. 5B is a plan view illustrating an inductive coil of the ICPgeneration system of FIG. 5A.

Referring to FIGS. 5A and 5B, an ICP generation system 400 may include adielectric tube 130 extending in a length direction; a first inductivecoil structure 410, which is provided to enclose the dielectric tube 130and to produce ICP in the dielectric tube 130; an RF power supply 140,which is configured to provide positive and negative powers havingopposite phases, to respectively supply positive and negative powers ofRF power to both ends of the first inductive coil structure, and tochange a driving frequency; a first main capacitor 121 provided betweena positive output terminal of the RF power supply and one end of thefirst inductive coil structure; and a second main capacitor 122 providedbetween a negative output terminal of the RF power supply and anopposite end of the first inductive coil structure.

the first main capacitor 121 and the second main capacitor 122 may havethe same capacitance (e.g., of second capacitance C2), and the secondcapacitance C2 may be two times the first capacitance C1 of theauxiliary capacitor.

Inductive coils may include first to fourth inductive coils 412, 414,416, and 418. The auxiliary capacitor may include first to thirdauxiliary capacitors 113, 115, and 117. All of the first to fourthinductive coils 412, 414, 416, and 418 may have the same inductance ofL1. All of the first to third auxiliary capacitors 113, 115, and 117 mayhave the same capacitance of C1. Each of the first to third auxiliarycapacitors 113, 115, and 117 may be depicted as a pair ofserially-connected imaginary capacitors and may have 2C1. Accordingly, aportion (2C1) of the first main capacitor 121, the first inductive coil412, and the imaginary capacitor (2C1) may constitute a resonancecircuit, thereby reducing the voltage overall.

Each of the inductive coils 412, 414, 416, and 418 may include a firstcircular arc portion 42 a, which has a portion opened in a firstdirection in a rectangular coordinate system and is provided on anarrangement plane to have a first central angle and a constant firstradius; a second circular arc portion 42 b, which is provided on thearrangement plane to have a second central angle less than the firstcentral angle, to have a second radius larger than the first radius, andto have the same center axis as a center axis of the first circular arcportion; a first connecting portion 43 a, which is provided on thearrangement plane to be connected to one end of the first circular arcportion and to extend in the first direction; a “U”-shaped firstcircular arc connecting portion 44 a, which is provided on thearrangement plane to connect an opposite end of the first circular arcportion to one end of the second circular arc portion; and a secondconnecting portion 43 b, which is provided on the arrangement plane tobe connected to an opposite end of the second circular arc portion andto extend in the first direction. The second central angle may be equalto or greater than 270°.

According to some embodiments of the inventive concept, a plasmageneration system may include an inductive coil structure, which isconfigured to suppress a capacitive coupling effect and to stably andefficiently generate ICP

According to some embodiments of the inventive concept, an auxiliarycapacitor is provided to serially connect inductive coils, whichconstitute an inductive coil structure of a plasma generation system, toeach other, and this makes it possible to distribute a voltage and toreduce the overall highest voltage.

According to some embodiments of the inventive concept, a plasmageneration system is configured to have the same electric potential atpositions, where each of inductive coils constituting an inductive coilstructure is in contact with a dielectric tube, and thus, it may bepossible to suppress occurrence of a parasitic capacitor, to improvedischarge stability, and to suppress a local ion sputtering.

While example embodiments of the inventive concepts have beenparticularly shown and described, it will be understood by one ofordinary skill in the art that variations in form and detail may be madetherein without departing from the spirit and scope of the attachedclaims.

What is claimed is:
 1. An inductively-coupled plasma (ICP) generationsystem, comprising: a dielectric tube extending in a length direction; afirst inductive coil structure to enclose the dielectric tube and toproduce ICP in the dielectric tube; an RF power supply configured toprovide positive and negative powers having opposite phases, torespectively supply positive and negative powers of RF power to bothends of the first inductive coil structure, and to change a drivingfrequency; a first main capacitor between a positive output terminal ofthe RF power supply and one end of the first inductive coil structure;and a second main capacitor between a negative output terminal of the RFpower supply and an opposite end of the first inductive coil structure,wherein the first inductive coil structure comprises: inductive coilsconnected in series to each other and at different layers, the inductivecoils having at least one turn at each layer; and auxiliary capacitorswhich are respectively between adjacent ones of the inductive coils todistribute a voltage applied to the inductive coils.
 2. The ICPgeneration system of claim 1, wherein each of the inductive coils has asame inductance of first inductance, each of the auxiliary capacitorshas a same capacitance of first capacitance, and a driving frequency ofthe RF power is controlled to coincide with a resonance frequency, whichis determined by the first inductance and the first capacitanceconnected in series to each other.
 3. The ICP generation system of claim2, wherein each of the first main capacitor and the second maincapacitor has a same capacitance of second capacitance, and the secondcapacitance is two times the first capacitance.
 4. The ICP generationsystem of claim 1, wherein each of the inductive coils is a 2- to 4-turnantenna.
 5. The ICP generation system of claim 1, further comprising asecond inductive coil structure to enclose the dielectric tube, toproduce ICP in the dielectric tube, and to have a same structure as thefirst inductive coil structure, the second inductive coil structurebeing spaced apart from the first inductive coil structure, wherein oneend of the second inductive coil structure is connected to one end ofthe first inductive coil structure, an opposite end of the secondinductive coil structure is connected to an opposite end of the firstinductive coil structure, and the first inductive coil structure and thesecond inductive coil structure are connected in parallel to each otherbetween the first main capacitor and the second main capacitor.
 6. TheICP generation system of claim 5, wherein each of the inductive coilsconstituting the first inductive coil structure and the second inductivecoil structure has a same inductance of first inductance, each of theauxiliary capacitors constituting the first inductive coil structure andthe second inductive coil structure has a same capacitance of firstcapacitance, and a driving frequency of the RF power is controlled tocoincide with a resonance frequency, which is determined by the firstinductance and the first capacitance connected in series to each other.7. The ICP generation system of claim 6, wherein each of the first maincapacitor and the second main capacitor has a same capacitance of secondcapacitance, and the second capacitance is four times the firstcapacitance.
 8. The ICP generation system of claim 6, wherein the oneend of the first inductive coil structure and the one end of the secondinductive coil structure are configured to be adjacent to each other,and the one end of the first inductive coil structure and the one end ofthe second inductive coil structure are connected to each other and areconnected to the first main capacitor.
 9. The ICP generation system ofclaim 1, wherein each of the inductive coils comprises: a first circulararc portion, which has a portion opened in a first direction in arectangular coordinate system and is on an arrangement plane to have afirst central angle and a constant first radius; a second circular arcportion, which is on the arrangement plane to have a second centralangle less than the first central angle, to have a second radius largerthan the first radius, and to have the same center axis as a center axisof the first circular arc portion; a first connecting portion, which ison the arrangement plane to be connected to one end of the firstcircular arc portion and to extend in the first direction; a “U”-shapedfirst circular arc connecting portion, which is on the arrangement planeto connect an opposite end of the first circular arc portion with oneend of the second circular arc portion; and a second connecting portion,which is on the arrangement plane to be connected to an opposite end ofthe second circular arc portion and to extend in the first direction.10. The ICP generation system of claim 1, wherein each of the inductivecoils comprises: a first circular arc portion, which has a portionopened in a first direction in a rectangular coordinate system and isprovided on an arrangement plane to have a first central angle and aconstant first radius; a second circular arc portion, which is on thearrangement plane to have a second central angle less than the firstcentral angle, to have a second radius larger than the first radius, andto have the same center axis as a center axis of the first circular arcportion; a third circular arc portion, which is on the arrangement planeto have a third central angle less than the second central angle, tohave a third radius larger than the second radius, and to have the samecenter axis as the center axis of the first circular arc portion; afirst connecting portion, which is on the arrangement plane to beconnected to one end of the first circular arc portion and to extend inthe first direction; a “U”-shaped first circular arc connecting portion,which is on the arrangement plane to connect an opposite end of thefirst circular arc portion with one end of the second circular arcportion; a “U”-shaped second circular arc connecting portion, which ison the arrangement plane to connect an opposite end of the secondcircular arc portion to one end of the third circular arc portion; and asecond connecting portion, which is on the arrangement plane to beconnected to an opposite end of the third circular arc portion and toextend in the first direction.
 11. The ICP generation system of claim 1,wherein each of the inductive coils comprises: a first circular arcportion, which has a portion opened in a first direction in arectangular coordinate system and is on an arrangement plane to have afirst central angle and a constant first radius; a second circular arcportion, which is on the arrangement plane to have a second centralangle less than the first central angle, to have a second radius largerthan the first radius, and to have a same center axis as a center axisof the first circular arc portion; a third circular arc portion, whichis on the arrangement plane to have a third central angle less than thesecond central angle, to have a third radius larger than the secondradius, and to have a same center axis as the center axis of the firstcircular arc portion; a fourth circular arc portion, which is on thearrangement plane to have a fourth central angle less than the thirdcentral angle, to have a fourth radius larger than the third radius, andto have a same center axis as the center axis of the first circular arcportion; a first connecting portion, which is on the arrangement planeto be connected to one end of the first circular arc portion and toextend in the first direction; a “U”-shaped first circular arcconnecting portion, which is on the arrangement plane to connect anopposite end of the first circular arc portion with one end of thesecond circular arc portion; a “U”-shaped second circular arc connectingportion, which is on the arrangement plane to connect an opposite end ofthe second circular arc portion to one end of the third circular arcportion; a “U”-shaped third circular arc connecting portion, which is onthe arrangement plane to connect an opposite end of the third circulararc portion to one end of the fourth circular arc portion; and a secondconnecting portion, which is on the arrangement plane to be connected toan opposite end of the fourth circular arc portion and to extend in thefirst direction.
 12. The ICP generation system of claim 6, wherein thefirst inductive coil structure and the second inductive coil structurehave a vertical mirror symmetry with reference to a point of thedielectric discharge tube, and current is vertically divided at a centerand then is collected at both ends.
 13. The ICP generation system ofclaim 6, wherein power input terminals of the inductive coils arearranged to maintain a uniform angle in an azimuth direction.
 14. TheICP generation system of claim 1, wherein at least a portion of theinductive coils is fixed by a ceramic mold.
 15. The ICP generationsystem of claim 1, further comprising a washer-shaped insulating spacer,which is between the inductive coils to electrically disconnect theinductive coils from each other.
 16. The ICP generation system of claim1, wherein the inductive coils comprise first to fourth inductive coilssequentially stacked, the auxiliary capacitor comprises first to thirdauxiliary capacitors, when compared with the first inductive coil, thesecond inductive coil is rotated counterclockwise by 90° and is belowand aligned with the first inductive coil, when compared with the secondinductive coil, the third inductive coil is rotated counterclockwise by90° and is below and aligned with the second inductive coil, whencompared with the third inductive coil, the fourth inductive coil isrotated counterclockwise by 90° and is below and aligned with the thirdinductive coil, one end of the first inductive coil is connected to apositive output terminal of the RF power supply through the first maincapacitor, an opposite end of the first inductive coil is connected toone end of the second inductive coil through the first auxiliarycapacitor, an opposite end of the second inductive coil is connected toone end of the third inductive coil through the second auxiliarycapacitor, an opposite end of the third inductive coil is connected toone end of the fourth inductive coil through the third auxiliarycapacitor, and an opposite end of the fourth inductive coil is connectedto a negative output terminal of the RF power supply through the secondmain capacitor.
 17. A substrate processing system, comprising: a processchamber configured to process a semiconductor substrate; and an ICPgeneration system configured to provide active species, which areprovided by plasma, into the process chamber, wherein the ICP generationsystem comprises: a dielectric tube extending in a length direction; afirst inductive coil structure to enclose the dielectric tube and toproduce ICP in the dielectric tube; an RF power supply configured toprovide positive and negative powers having opposite phases, torespectively supply positive and negative powers of RF power to bothends of the first inductive coil structure, and to change a drivingfrequency; a first main capacitor between a positive output terminal ofthe RF power supply and one end of the first inductive coil structure;and a second main capacitor between a negative output terminal of the RFpower supply and an opposite end of the first inductive coil structure,wherein the first inductive coil structure comprises: inductive coilsconnected in series to each other and at different layers, the inductivecoils having at least one turn at each layer; and auxiliary capacitors,which are respectively between adjacent ones of the inductive coils todistribute a voltage applied to the inductive coils.
 18. An inductivecoil structure to enclose a dielectric tube and to produce ICP in thedielectric tube, wherein the inductive coil structure comprises:inductive coils connected in series to each other and at differentlayers, the inductive coils having at least one turn at each layer andhaving the same structure; and auxiliary capacitors, which arerespectively between adjacent ones of the inductive coils to distributea voltage applied to the inductive coils.
 19. The inductive coilstructure of claim 18, wherein each of the inductive coils comprises: afirst circular arc portion, which has a portion opened in a firstdirection in a rectangular coordinate system and is on an arrangementplane to have a first central angle and a constant first radius; asecond circular arc portion, which is on the arrangement plane to have asecond central angle less than the first central angle, to have a secondradius larger than the first radius, and to have a same center axis as acenter axis of the first circular arc portion; a third circular arcportion, which is on the arrangement plane to have a third central angleless than the second central angle, to have a third radius larger thanthe second radius, and to have a same center axis as the center axis ofthe first circular arc portion; a first connecting portion, which is onthe arrangement plane to be connected to one end of the first circulararc portion and to extend in the first direction; a “U”-shaped firstcircular arc connecting portion, which is on the arrangement plane toconnect an opposite end of the first circular arc portion with one endof the second circular arc portion; a “U”-shaped second circular arcconnecting portion, which is on the arrangement plane to connect anopposite end of the second circular arc portion to one end of the thirdcircular arc portion; a second connecting portion, which is on thearrangement plane to be connected to an opposite end of the thirdcircular arc portion and to extend in the first direction.
 20. Theinductive coil structure of claim 18, wherein each of the inductivecoils comprises: a first circular arc portion, which has a portionopened in a first direction in a rectangular coordinate system and isprovided on an arrangement plane to have a first central angle and aconstant first radius; a second circular arc portion, which is on thearrangement plane to have a second central angle less than the firstcentral angle, to have a second radius larger than the first radius, andto have a same center axis as a center axis of the first circular arcportion; a third circular arc portion, which is on the arrangement planeto have a third central angle less than the second central angle, tohave a third radius larger than the second radius, and to have a samecenter axis as the center axis of the first circular arc portion; afourth circular arc portion, which is on the arrangement plane to have afourth central angle less than the third central angle, to have a fourthradius larger than the third radius, and to have a same center axis asthe center axis of the first circular arc portion; a first connectingportion, which is on the arrangement plane to be connected to one end ofthe first circular arc portion and to extend in the first direction; a“U”-shaped first circular arc connecting portion, which is on thearrangement plane to connect an opposite end of the first circular arcportion with one end of the second circular arc portion; a “U”-shapedsecond circular arc connecting portion, which is on the arrangementplane to connect an opposite end of the second circular arc portion toone end of the third circular arc portion; a “U”-shaped third circulararc connecting portion, which is on the arrangement plane to connect anopposite end of the third circular arc portion to one end of the fourthcircular arc portion; and a second connecting portion, which is on thearrangement plane to be connected to an opposite end of the fourthcircular arc portion and to extend in the first direction.